Water-tube boiler



K. VORSMANN. WATER TUBE BOILER. APPLICATION FILED JULY 5, 1911.

x v I 45% gigmi:

INVENTOR" 4 KARkVbRSMANN W4 ATTORNEY- EWMLQW .FLS

KARL VURSIVIANN, OF BRUNN, AUSTRIA.

warnnnunn BOILER.

f..,i:23,3'?55. Specification of Application filed July 5,

I To aZZ 10/10 172, it may concern:

pile, and residing at Brunn, Austria, Moravia, have invented new and useful Improvements in ater-Tube Boilers; and I do hereby declare the following to be a full, clear, and exact description of the same.

' My invention relates to water tube boilers and more especially to boilers of the divided header type such as are known for instance under the denomination of Babcock & Nilcox boilers, Its particular object is an improved way of making the chambers connecting the headers to the upper boiler or steam drum. As is well known these connecting chambers are made from. a sheet iron blank by pressing, a flange serving for riveting them to the upper boiler.

Up till now the production of these transverse chambers had been connect-ed with con.- siderable difficulty, necessitating extensive and complicated pressing work to be carried out in four steps or'heats.

lVith the method of working according to the present invention the difficulties encountered hitherto are totall avoided and the work, pieces are produced and finished in two steps or heats.

' In carrying out'my invention I proceed substantially as follows: The flat bottom of the chamber is pressed in one piece on a stamping press in the first step or heat, by aid of a suitable set of dies in a circle of predetermined radius with. the curvature upwards- At the same time the lower sides of the pocket-shaped connections receive their final shape and the cylindrical flange isb ent to a radius larger than its radius in a finished state. ..-he second step, to be carried out in a second. heat, consists in reducing-the curved bottonnby aid of a second set of dies, to a flat shape, bending the lower sides of the pocket-shaped connections towards the presser die and. at the same time upwards and bringing the cylindrical fiange to its final position. r

In the drawings affixed to this specification and forming part. thereof,

Fig. 1 is a vertical longitudinal section of a connecting chamber of the kind spoken of, and

Fig. 2 is a cross section of the central part of said chamber.

Figspii to 5 are vertical cross sections of preferred forms of the top and bottom dies Letters Patent.

Patented July 18, 1922. 1917. Serial No. 178,724.

to be used in carrying out the single steps of the process of manufacture of such chambers the working piece being shown in longitudinal section in position between the dies, Fig. 3 illustrating the first step, while Figs. 4': and 5 respectively illustrate two succeeding phases of the second step.

Referring to the drawings, Fig. 1 shows the oblong chamber a open on top and being provided with a substantially flat bottom 6 having circular holes 0 formed therein, said holes being designed to receive the end of a row of tubes (not shown). As can be seen with reference to Fig. 2, the bottom has the well-known form of a gutter, in order to facilitate the connection between the bottom and the tubes. (Z d. are the pocket-shaped ends of the chamber, and e is a flange curved in the are a circle so as to allowthe cham ber to be'fixed to the or steam drum.

In the first step, now, a sheet metal blank of suitable configuration is subjected to the action of the set of dies 7, 9' shown in Fig, 3,

hydraulic pressure being preferably employed. The bottom die f comprises an oblong convex bottom part 7 bordered by two diverging vertical curved end portions 7 and two substantially vertical fiat side portions 7, the upper edges 7 of the end per tions f being inclined towards the center of the die, while the side portions f have an upper edge f curved so as to almost descend towards the central part of the bottom 7.

The top dieg is exactly the reverse of'thej bottom die described above.

By aid of these dies the blank is shaped as shown in Fig. 3 of the drawings, the bottom Z2 being curved upwards in the arc of circle, while the faces of the bottom die coacting with the corresponding faces of the top die shape thelcylindrical flange 0 after a. radius greater than the radius of the finished flange. The side portions of the pocket;

shaped connections are finished at the same time. The end portions of the bottom t adjoining the narrow sides of the chamber are pressed flat in the first operation, it being necessary to impart to them their final shape before starting the second operation as will. be seen hereafter.

The shapes produced by aid of the set of dies described above are then finished by aid of the set of dies represented in Figs. iand 5. The bottom die it has a substantially flat bottom 7L1, its side walls are cut away along a circle segment 72?. The top die 11 has an oblong substantially flat bottom i flanked on both sides by downward curved parts 2' approidmately fitting in the cut out side portions it of the bottom die. The length of the bottom part i isconsiderably less than the length of bottom part [L1 and substantially equal to the distance between the uppermost inner edges of the end portions cl of the finished chamber.

The work piece resulting from the treatment in the dies f, 9, after h aving been heated once more, is inserted in the bottom die 12 as shown in Fig. l, and pressure is then applied to the to die i so as to force it vertically down upon the work piece. In descending the bottom 2' of the top die presses the convex bottom 6 of the wor;

piece downwards, at the same time stretching and flattening it, thereby forcing the diverging end portions cl ot' the work piece into the bottom die whose length is less than the greatest cuter length of the work piece.

The end portions (Z are thereby caused to verge towards each other; on the other hand the convex bottom 7) in being flattened out causes the lower parts of the end portions (Z to till the corners of the bottom die hollow. At the same time the flange c is bent to shape between the curved parts i and 72, oi the top and bottom dies respectively and the upper parts of the end portions cl are thereby brought to bear 'againstthe curved end faces of the top die. These operations are illustrated in Fig. 5. The top die 2' having a smaller diameter than the hollow of the bottom die will no more act upon the parts of the work piece bottom adjoining the end portions (5 and for this reason, as stated above,these parts are finished already in the first operation.

After the top die 11 has been withdrawn from the bottom die h, the work piece is finished, save for the tube holes, which have i to be drilled into its bottom.

Itis easy to. see that the new process here described. affords great advantages as compared with the old methods where two heats were required for sh aping the pocket-shaped parts (Z, one alter the other, whereupon in a third heat the side walls and the flat bottom were produced, a fourth heat being requiredtor forming and finishing the circular flange. The dies forming part of the invention are made in one piece each, thus securing an absolute uniformity of shaping,

1. A process tor the manufacture of headers for steam boilers, comprising shaping a blank between a first set of dies to have an upwardly curved bottomand surrounding side and end walls provided with outstanding flanges, and subsequently flattening the bottom and thereby drawing in the top portions of the end walls towards each other between another set of dies.

2. A process for the manufacture of head ers for steam boilers, comprising shaping a blanltbetween a first set 01 dies to have an upwardly curved. bottom and surroundinc; side and end wallsprovided with out staiulingr flanges, and subsequently. flattening: the bottom and thereby drawing in the top portions of the end walls towards each other between another set of dies, the male member of which has the distance between its eml faces equal to the distance between the upper contracted portions of the end walls of the finished header.

3. A pro *ess for the manufacture of headers for steam. boilers, comprising shaping a blank between: a first set of dies to have an upwardly curved bottom and surrounding; side and end walls, the side walls being provided with outstanding flanges having a preliminary curvature in the direction 01, the cuiwature oi. the boiler which the finished header is designed to lit, and subsequently flattening the hottom and thereby drawing in the top por- V tionsot the end walls towards arch other and shaping the flanges ot the side walls to a can curvature correqponditng to the curvature of the boiler between another set of dies. 7 In testimony whereof, I have signed my name to this specification in the presence of two $l.ll)S(t1'l.l):l1lg witnesses.

KARL VORSMANN.

Witnesses:

JOHN F. SIMoNs, Monrrz SCHMALKA. 

